The main function of the centralized maintenance of an aircraft is to make, in real time or at the end of the flight, a diagnosis of the general situation of the aircraft on the basis of a summary of the fault messages received from the various items of equipment of the aircraft.
Maintenance also fulfils other functions such as the correlation of the fault messages received with the alarms received at the level of the flight deck, the conduct of the particular tests on the equipment undertaken on request by an operator or the drafting of reports intended for the ground maintenance teams, reports containing a log of the fault messages issued by the various items of equipment of the aircraft and of the alarms presented to the crew as well as a summary of the fault messages, carried out as a last resort. More generally, the reports contain all the information about the operating states of the equipment, liable to ease the work of the ground maintenance team.
Conventionally, through its functionality, the centralized maintenance system is connected to several tens of items of equipment of the aircraft, each being able potentially to generate tens or indeed hundreds of fault messages.
The development and the maintenance of such a system is complex and expensive since it depends not only on the technical specifications of the aircraft's equipment but also on the operational customs and procedures of aircraft manufacturers and operators.
The function adheres strongly to the aeroplane system definition. Fine tuning is lengthy and complex due to the very large number of connected items of equipment to be processed (more than 100 items of equipment per aeroplane) and to the diversity of the protocols. The lengthening is significant for system integration and the maturation of the diagnosis performance.
Moreover this fine tuning necessitates the involvement of personnel from different cultures, be it the equipment supplier (Member system), the designer of the maintenance system or the designer of the aircraft.
The difficulty with this multiplicity and with this diversity is that the maintenance information must be captured and formalized in an unambiguous, complete and consistent manner.
Hitherto information capture has been carried out for the major part through aircraft systems specification documents. No formalism is applied to guarantee the homogeneity, consistency and completeness of the information.
Moreover this capture phase is lengthy, iterative and made complicated by the large number of items of equipment to be managed and the diversity of the parties involved in the fine tuning of the system.
Defects not detected during this phase will disturb and prolong the integration activities, and necessitate new capture iterations to obtain a complete, accurate and unambiguous definition of the system data.
Solutions exist which make it possible to ease the inputting of the information via computing tools but none proposes to integrate it into a wider solution integrating an input device, data verification mechanisms, and implementing a process which will tailor the information level shared and define all of the information that may be furnished by the diverse designers of the maintenance system.
So there exists the requirement for an overall solution which makes it possible to capture in a complete manner the maintenance requirements of an aircraft.